A typical electric arc furnace for a melting or smelting operation comprises a refractory-lined enclosure in which feed material is melted by one or more cylindrical electrodes that pass through ports in the furnace roof. Electric power, often as arcs, is emitted from the lower ends of the electrodes to melt the charge materials and maintain a bath of molten material within the furnace. The electrode tips are gradually and continuously consumed during furnace operation. To compensate for electrode consumption, the electrodes are fed downwardly into the furnace, while new sections are added to the tops of the electrodes.
The position of the electrode tip in relation to various furnace contents, such as slag and metal bath levels, as well as the position in relation to various fixed components such as the taphole and hearth, is an important parameter for operational control of the furnace. The position of the tip in relation to these various components has a direct and appreciable effect on a measure of furnace efficiency, on an ability of the furnace to operate at the desired power input as well as on the metallurgical reactions therein. Thus, electrode tip position and control relate to production of a low cost, yet high quality product.